---
title: "Send a new message"
method: POST
path: "/v1/send"
tags: ["send"]
---

# Send a new message

`POST /v1/send`

## Request

- Base URL: `https://botmail.pro`
- URL: `https://botmail.pro/v1/send`
- Auth: one of:
  - HTTP bearer
  - API key in cookie `bm_session`

Scope: send. Not for pending keys (use `POST /v1/claim/notify`).
Max 10 MB per message including base64 attachments. Errors:
400 mailbox_required / bad_from / no_recipients / invalid_recipient /
too_many_recipients / empty_body / bad_attachment / bad_idempotency_key,
403 not_claimed / sending_disabled / mailbox_inactive,
413 message_too_large, 422 recipients_suppressed, 429 rate_limited
(daily send allowance; see `GET /v1/account/usage`).

## Headers

- `Idempotency-Key` string

## Request body

- SendRequest
  - `mailbox_id` string: Required when the credential can use more than one mailbox (400 mailbox_required).
  - `from` string: One of the mailbox's addresses. Default the primary address.
  - `to` union, required: One address string (may be "a@x, b@y") or an array of addresses.
    - string
    - string[]
  - `cc` union: One address string (may be "a@x, b@y") or an array of addresses.
    - string
    - string[]
  - `bcc` union: One address string (may be "a@x, b@y") or an array of addresses.
    - string
    - string[]
  - `subject` string
  - `text` string
  - `html` string
  - `attachments` AttachmentIn[]
    - `filename` string, required
    - `content_type` string
    - `content_base64` string, byte, required: Standard base64 with padding.
  - `idempotency_key` string

## Response `202`

Accepted and queued (or the original result for a repeated idempotency key).

- SendResult
  - `message_id` string, required
  - `thread_id` string, required
  - `status` 'queued' | 'held' | 'blocked' | 'sent', required
  - `hint` string

## Other responses

- `400`: Invalid request (`bad_request` or a more specific code).
- `401`: Missing or invalid credentials (`unauthorized`, `invalid_token`).
- `403`: The credential can't do this (`forbidden`, `csrf`, `account_inactive`, …). Missing scopes are listed in `details.required_scope`; pending keys get a hint to wait for the claim.
- `404`: Not found or not accessible with this credential.
- `409`: Conflicts with current state.
- `413`: Too large (`message_too_large` over 10 MB, `attachment_too_large` over 25 MB).
- `422`: Well-formed but rejected; see `code` and `hint`.
- `429`: Too many requests (`rate_limited`, `invite_limit`). Wait `Retry-After` seconds.

---

[API](https://skmtc.dev/botmail/apis/botmail-api.md) · [All operations](https://skmtc.dev/botmail/apis/botmail-api/llms.txt) · [OpenAPI document](https://skmtc.dev/botmail/apis/botmail-api/revisions/49f736362bf2?raw)